Lattice Semiconductor warned investors this morning that its fourth-quarter financial results will be worse than forecast.

"Softening of demand" in its communications business pushing the Hillsboro company's sales down between 14 and 17 percent from last quarter.Lattice had said previously that it expected a decline between 4 and 9 percent.

Simultaneously, Lattice announced it will pay $62 million in cash for a five-year-old Silicon Valley mobile chip company called SiliconBlue Technologies.